A long term evolution (LTE, Long Term Evolution) standard Rel-8/9/10 communications system improves system performance by adopting a dynamic scheduling technology, that is, a base station (eNB, evolved Node B) schedules and allocates resources according to a channel situation of a user equipment, so that a scheduled user performs transmission on an optimal channel of the user equipment
However, the problem of a limited capacity of a PDCCH (Physical Downlink Control Channel, physical downlink control channel) is much highlighted in further evolution of an LTE Rel-10 system. The multi-user MIMO (Multiple-Input Multiple-Output, multiple-input multiple-output) is increasingly applied in an evolution system to improve the spectral efficiency of the system, which increases the number of user equipments scheduled simultaneously, and therefore more PDCCHs are required. Based on this, an existing PDCCH is enhanced, that is, a part of resources are divided from an original PDSCH area to transmit an enhanced PDCCH (e-PDCCH, Enhanced Physical Downlink Control Channel, enhanced physical downlink control channel). In this way, the resources allocated to the e-PDCCH are greatly flexible and are not limited to three OFDM (Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing) symbols anymore, thereby improving the capacity of the PDCCH or the number of user equipments scheduled simultaneously; meanwhile, the e-PDCCH may also adopt a DMRS (UE-specific Reference Signal, demodulation reference signal) based transmission manner and may implement spatial reuse to improve the transmission efficiency of the control channel.
Currently, when data is transmitted in a DMRS based transmitting diversity manner, after space time block code (Alamouti) coding is performed separately on two consecutive REs (Resource Element, resource element) on a frequency domain and two consecutive REs on a time domain, the data is transmitted in two manners, namely, SFBC (Space Frequency Block Coding, space frequency block coding) and STBC (Space Time Block Coding, space time block coding), simultaneously. However, because data of an e-PDCCH is transmitted by adopting two transmitting diversity solutions, the complexity of transmitting and receiving on the eNB and the UE (User Equipment, user equipment) is increased.